Semiconductor memory is an electronic data storage device implemented on a semiconductor-based integrated circuit. Semiconductor memory has many different types, and has faster access times than other data storage technologies. For example, a byte of data can often be written to or read from semiconductor memory within a few nanoseconds, while access times for rotating storage, such as hard disks, is in the range of milliseconds. For these reasons, among others, semiconductor memory is used as a primary storage mechanism for computers to hold data computers are currently working on, among other uses.